JPH06166386A - Rear structure of automobile - Google Patents

Abstract

PURPOSE:To improve an aerodynamic characteristic by reducing air resistance effectively by means of simple constitution by providing an arch vortex eliminating means to eliminate an arch vortex generated in an arch shape toward the upper part from both left and right side portions of a tail gate provided at the rear vehicle body of an automobile. CONSTITUTION:A gate type obstacle 8 consisting of a pair of left and right leg bodies 6 and a platelike body 7 provided between the upper end portions of the leg bodies 6 is provided on the upper surface of a trunk lid, and the obstacle 8 is supported turnably with the support axes of the lower end portions of the leg bodies 6 as fulcrums, and at the same time up an down operation is conducted by means of a drive means consisting of air cylinders 10 at the upper end portions of a rear fender panel 5. At the time of automobile travel, cylinder rods 11 are projected to extended positions according to air fed to the air cylinders 10, and the leg bodies 6 are supported in a standing-up state. By positioning the platelike body 7 of the obstacle 8 at a position opposite to the upper part of an arch vortex, the arch vortex being generated above the trunk lid 4 is deterred.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile rear body structure improved to obtain excellent aerodynamic characteristics.

[0002]

2. Description of the Related Art Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 4-5112, the shape of a rain cut sun visor of an automobile has been devised to allow the vehicle to run with the upper end of the side window open. In order to prevent a strong airflow from flowing into the vehicle compartment through the opening, it is possible to prevent noise and air resistance from increasing due to the airflow.

[0003]

As described above, the air resistance caused by the flow of the traveling wind has a great influence on the fuel consumption and the drivability of the automobile, and this traveling wind is extremely complicated along the surface of the vehicle body. It is known to form flows and eddies. Therefore, in order to improve the aerodynamic characteristics of the automobile, it is desired to accurately elucidate the flow of the traveling wind and to devise the structure of the vehicle body according to the flow of the traveling wind. As a result of repeated experiments conducted by the present inventor based on the above request, it was discovered that a special vortex flow was generated on the trunk lid of the rear vehicle body, and this vortex flow significantly affects the aerodynamic characteristics of the automobile. Found.

The present invention has been made in view of the above points, and effectively reduces the air resistance caused by the flow of traveling wind with a simple structure and remarkably improves the aerodynamic characteristics of an automobile. It is an object of the present invention to provide a rear body structure of an automobile that can be used.

[0005]

The invention according to claim 1 is
Arch tail vortex elimination means for eliminating arch vortices generated in an arch shape from the left and right side portions of a tailgate provided on the rear body of an automobile toward the upper side thereof is provided.

According to the second aspect of the present invention, the arch vortex is erased by an obstacle installed in the arch vortex generating portion.

According to a third aspect of the present invention, an obstacle for extinguishing the arch vortex can be stored in a storage portion formed in the rear vehicle body.

According to a fourth aspect of the invention, the arch vortex eliminating means is provided in the arch vortex generating portion, which is a blowing means provided with a blowing hole for blowing gas.

According to a fifth aspect of the present invention, there is provided arch vortex erasing means comprising suction means having suction holes for sucking air in the arch vortex generating portion.

According to a sixth aspect of the present invention, the arch vortex erasing means including the sound wave transmitting means for transmitting a sound wave is provided in the arch vortex generating portion.

[0011]

According to the first aspect of the present invention, the aerodynamic characteristics of the automobile are improved by eliminating the arch vortex generated on the trunk lid when the automobile is running by the eliminating means.

According to the second aspect of the present invention, the generation of the arch vortex is obstructed by the obstacle installed at the arch vortex generating portion on the tailgate, and as a result, the arch vortex is erased.

According to the third aspect of the present invention, by storing the obstacle in the storage portion of the rear vehicle body when not in use, such as when the vehicle is stopped, it is possible to prevent the appearance of the rear vehicle body from being deteriorated by the presence of the obstacle. Can be prevented.

According to the fourth aspect of the present invention, the arch vortex is extinguished by the airflow blown to the arch vortex generating portion on the tailgate.

According to the fifth aspect of the present invention, the air located in the arch vortex generating portion on the tailgate is sucked, so that the generation of the arch vortex is hindered.

According to the invention described in claim 6, the arch vortex is destroyed by the sound wave transmitted to the arch vortex generating portion on the tailgate.

[0017]

1 and 2 show an embodiment of the rear body structure of an automobile according to the present invention. The rear vehicle body includes a pair of left and right rear pillars 2 projecting downward from a rear end portion of a roof panel 1, a rear window 3 installed therebetween.
It has a trunk lid 4 provided at the lower end thereof and a rear end panel 5 provided at the rear end of the rear vehicle body.

A gate-shaped obstacle 8 consisting of a pair of left and right legs 6 and a plate-like body 7 placed between the upper ends of the legs 6 is provided on the upper surface of the trunk lid 4. . The obstacle 8 is rotatably supported by a support shaft 9 provided at the lower end of the leg 7 as a fulcrum, and is driven by a driving means including an air cylinder 10 installed at the upper end of the rear fender panel 5. It is configured so that it can be driven to perform an undulating operation.

That is, when the vehicle is running, the cylinder rod 11 projects to the extended position in response to the air supplied from the air source (not shown) to the drive portion of the air cylinder 10, so that the leg 6 is raised. It is supposed to be supported. When the obstacle 8 is in an upright state, the plate-like body 7 extends above the trunk lid 4 from a rear end portion of the roof panel 1 toward an upper end portion of the rear end panel 5, and the roof panel 1 The height is set so as to be located between the rear end portion and an extension line b extending rearward.

Further, when the automobile is stopped, air is drawn out from the drive portion of the air cylinder 10 and the cylinder rod 11 is retracted to the contracted position, which causes the obstacle 8 to move the obstacle 8 to the trunk lid 4 as shown in FIG. It is configured so that it lays on top. Also, the trunk lid 4
A concave portion 12 for storing the obstacle 8 in the lying state is formed on the upper surface (see FIG. 1).

The vehicle having the obstacle 8 has a vehicle body air resistance coefficient Cd which is higher than that of an ordinary vehicle having no obstacle 8.
Can be improved. That is, as shown in FIG. 4, as a result of repeating various experiments for measuring the velocity fluctuation of the air flow generated in the rear vehicle body according to the running of the vehicle, the pressure fluctuation on the trunk lid 4, the air resistance acting on the vehicle body, etc. ,
In addition to a pair of left and right strong swirling flows A flowing along the side surface of the vehicle body, which is conventionally known, and a main flow B of air flowing obliquely downward from the roof panel 1, both left and right side parts of the tailgate including the trunk lid 1 described above. It was discovered that an arc-shaped vortex flow (hereinafter referred to as an arch vortex) C is generated above it.

Then, as shown in FIG. 5 and FIG. 6, a rod 13 having a diameter of about 15/1000 of the entire length of the vehicle body is installed above the trunk lid 4 so as to extend in the vehicle width direction. The rod 13 from the front end
To the distance X and the rod 13 on the trunk lid 4
The air resistance coefficient C of the vehicle body can be changed by changing the installation height H of the vehicle
When an experiment for measuring d was conducted, data were obtained as shown in FIG. 7. In this data, the circles have a distance X of 0 mm, the triangles have a distance X of 70 mm, and the squares have a distance X of 14 mm.
It shows that it is 0 mm.

Based on the above data, the installation position of the rod body 13 is 0 or 70 mm from the front end of the trunk lid 4.
Set the installation height H of the rod 13 to 110 to 130
It can be seen that when set to about mm, the air resistance coefficient Cd of the vehicle body is improved by about 10% as compared with the other cases. As a result, an obstacle formed by the rod body 13 and the like is provided between the straight line a extending from the rear end of the roof panel 1 toward the upper end of the rear end panel 5 and the extension line b extending rearward from the installation position of the roof panel 1. By installing an object and destroying an upper ⅓ region of the upper portion of the arch vortex C generated at a position slightly rearward of the front end of the trunk lid 4 by the obstacle, the arch vortex C is blown by air. It was confirmed that the resistance coefficient Cd was improved by about 10%.

Therefore, the gate-shaped obstacle 8 is installed on the trunk lid 4 as described above, and the plate-like body 7 of the obstacle 8 is located at a position corresponding to the upper part of the arch vortex C, that is, the trunk lid when the vehicle is running. 4 is located above the straight line a and the extension line b, the trunk lid 4
The generation of the arch vortex C on the upper side is effectively prevented by the plate-like body 7, and the air resistance coefficient Cd of the vehicle body is thereby prevented.
Can be significantly reduced.

Further, in the above-described embodiment, since the air cylinder 10 for supporting the gate-shaped obstacle 8 so as to be able to rise and fall and for raising and lowering the obstacle 8 is provided, the obstacle 8 can be erected when the vehicle is running. As a result, the arch vortex C can be effectively eliminated, and the obstacle 8 can be laid down so as not to get in the way when the vehicle is stopped. Then, the recess 1 is formed on the upper surface of the trunk lid 4.
2 is formed, and the obstacle 8 is stored in the storage portion formed by the recess 12 to prevent the obstacle 8 from protruding above the trunk lid 4 and impairing the appearance of the rear vehicle body when not in use. You can

Instead of the gate-shaped obstacle 8, as shown in FIG. 8, a supporting member 14 made of an elastic body such as a piano wire.
It is also possible to have a structure in which an obstacle 16 composed of a sphere 15 fixed to the upper end of the obstacle 16 is installed. According to this structure,
The supporting member 14 vibrates while the vehicle is running and the sphere 15
Because of the oscillating displacement, there is an advantage that the arch vortex C formed in various shapes depending on the traveling speed of the automobile, the shape of the vehicle body, and the like can be surely eliminated.

Further, as shown in FIG. 9, an air blowing means having an air blowing hole 17 formed in the lower side of the rear window 9 and a lead-out pipe for leading the air introduced into the vehicle body to the air blowing hole 17 Is provided, and the air blowing hole 17 is provided.
Therefore, the arch vortex C may be blown out by blowing air to the generation portion of the arch vortex C.
The air blowout hole 17 may be formed in the front side of the trunk lid 4.

Further, as shown in FIG. 10, the air suction holes 18 formed on the side and upper sides of the trunk lid 4 and the air formed on the front side of the roof panel 1 and the engine hood 19 are formed. Suction hole 20 and a connecting duct 2 that connects the suction hole 20 and the suction hole 18
1 may be provided with a suction means. In the case of such a configuration, the air located at the generation portion of the arch vortex C is sucked into the connection duct 21 from the suction hole 18 according to the negative pressure acting on the installation portion of the air suction hole 20. This prevents the generation of arch vortices in this portion.

Further, a sound wave generating means such as a speaker for emitting a low frequency sound wave is provided, and the arch vortex C is generated from this sound wave generating means.
The arch vortex C may be extinguished by generating a sound wave toward the generation section and applying a pressure to the generation section of the arch vortex C by the sound wave. In this case,
Since the generation timing of the sound wave can be adjusted arbitrarily, for example, a detection means for detecting the generation state of the arch vortex C is provided, and the generation timing of the sound wave is controlled according to the pressure fluctuation state detected by the detection means. As a result, the arch vortex C can be effectively eliminated.

That is, in order to confirm the changing state of the air flow caused by the arch vortex, a test was conducted to measure the air flow velocity at the central portion and the left and right side portions of the arch vortex C. As shown in FIG. It has been confirmed that air flows in opposite directions are generated on the left and right sides of the arch vortex C. Therefore, in order to cancel the pressure fluctuations generated in the left and right side portions of the arch vortex C corresponding to the changing state of the air flow, by separately emitting the sound waves at the different timings, the energy loss is not generated. The arch vortex C can be effectively eliminated.

Further, as shown in FIG. 12, an obstacle composed of a shield plate 23 is installed at the rear end portion of the rear pillar 2 so as to be retractable, and the shield plate 23 is projected so that the air in this portion is projected when the automobile is running. By blocking the flow, the arch vortex C may be prevented from being generated. In this case, there is an advantage in that the shielding plate 23 can reduce the yawing moment generated in response to the side wind acting when the vehicle is running.

[0032]

As described above, according to the present invention, an erasing means for eliminating arch vortices generated in an arch shape is provided on the tailgate such as a trunk lid, and the arch vortex is formed on the tailgate when the vehicle is running. Since it is configured so as to prevent the generation of the vehicle, it is possible to effectively prevent an increase in the air resistance coefficient Cd of the vehicle body due to the arch vortex with a simple configuration.
There is an advantage that the aerodynamic characteristics of the vehicle body can be improved to improve fuel efficiency.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a rear body structure of an automobile according to the present invention.

FIG. 2 is a side view showing a standing state of an obstacle.

FIG. 3 is a side view showing a fallen state of an obstacle.

FIG. 4 is an explanatory diagram showing a generation state of an arch vortex.

FIG. 5 is a perspective view showing an installed state of a rod body used in a wind tunnel experiment.

FIG. 6 is an explanatory view showing an installation position of the rod body.

FIG. 7 is a graph showing data of the wind tunnel experiment.

FIG. 8 is a perspective view showing a second embodiment of the rear body structure of an automobile according to the present invention.

FIG. 9 is a perspective view showing a third embodiment of the rear body structure of an automobile according to the present invention.

FIG. 10 is a side view showing a fourth embodiment of the rear body structure of an automobile according to the present invention.

FIG. 11 is a time chart showing a change state of the airflow caused by the arch vortex.

FIG. 12 is a perspective view showing still another embodiment of the present invention.

[Explanation of symbols]

 4 Trunk lid (tailgate) 8 Obstacle (erasing means) 12 Recess (storage) 16 Obstacle (erasing means) 17 Blowing hole 18 Suction hole 23 Shielding plate (erasing means) C Arch vortex

Claims (6)

[Claims] 1. An arch vortex erasing means for erasing an arch vortex generated in an arch shape from both left and right side portions of a tailgate provided on a rear body of an automobile toward an upper side of the tailgate. Rear body structure of the car. 2. The rear vehicle body structure according to claim 1, wherein the arch vortex is eliminated by an obstacle installed in the arch vortex generating portion. 3. The rear vehicle body structure for an automobile according to claim 2, wherein the obstacle for eliminating the arch vortex can be stored in a storage portion formed in the rear vehicle body. 4. The rear body structure of the automobile according to claim 1, wherein the arch vortex generating portion is provided with an arch vortex erasing means including a blowing means having a blowout hole for blowing gas. 5. The rear vehicle body structure according to claim 1, further comprising an arch vortex erasing unit including a suction unit having a suction hole for sucking air in the arch vortex generating unit. 6. The rear vehicle body structure according to claim 1, wherein arch vortex generation means is provided with means for eliminating arch vortices, which comprises sound wave transmission means for transmitting sound waves.